Electric geateb and its mode of manttfactubb



L. P. HYNES ELECTRIC HEATER AND ITS MODE oF MANUFACTURE Aug- Filed Jan. 26, 1923 2 Sheets5heet 1 mvENToR. 5E 0. Hna/5.

ATTORNE Au'g. 26 1924. 1,506,065

| P. HYNEs ELECTRIC HEATER A ND ITS MODE OF MANUFACTURE Filed Jan. 26, 1923 2 Sheets-Sheet 2 jnnnnnffliiie i iff" 1L., M. @W

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Patented Aug. 26, 1924. l

AUNITED STATES rxPATENT orrlcl-z.

LEE P. HYNFS, 0F ALBANY, NEW YORK, ASSIGNOB TO CONSOLIDATED CAB-HEATING 00mm, OIF ALBANY NEW YORK, A CORPORATION 0F WET VIRGINIA.

ELETTRICI HEATER A NJ) ITS MODE 0F KLNUFACTURE.

Application med January 26, 1922. Serial No. 531,956.

To all whom it may concem:

Be it known that I Lnn P. Hynes, a citim of the United states, residing at A1- bany, in the county of Albany and State of New York, have invented certain new and useful Im rovements in Electric Heaters and Their de of Manufacture, the following being a full, clear, and exact disclosure of the one form of m invention which I at present deem prefera le.

ll`o1` a detailed description of the present form of my invention, reference may be had to the following specilicationl and to the accompanying drawings forming a part thereof wherein- Irig. 1 is a side elevation partly in section of my heater;

Ii`igs. 2 and`3 show the terminal for the co1 y Fig. 4 illustrates the mode of manufacture; l

Fie'. 5 shows the heater coil as a separate Figs. 6, 7, 8, 9 and 10 show modifications.

My invention relates to certain improvements in the heater shown in my application of October 18th, 1921, Serial No. 508,542, wherein a tubular shell of metal is rolled or pressed longitudinally into a smaller ribbed tube and contains a parallel inside lining tube of refractory insulation in which the heatin coil lies closely. I have now devised a muc better form of end-seal and termitral-connector for such heater while I also make a better article by first shaping the metallic shell and then, while 'the linin tube is inside of it, passing it between two eeply grooved rollers whereby the edges of the roller grooves draw the metal in around the lining on each side. The lining tube is thus gripped by and retained in place inside the shell while the coil is being inserted or threaded, through it. Then the coil lies therein so loosely that it may readily be pulled out and re laced. This supplementary treatment a o insures a more intimate association of the tube and shell, and hence a better transmission of heat to the latter.

I also make the heater coil a separate article of manufacture available for replacements, by providing it with permanent terminals of a novel kind between which a predetermined length of wire is included t0 insure against overheating and destruction of the coil.

Referrin to the drawing, 1 represents the steel tue, originally of plain cylindrical form, but for the reater part of its len compressed or rold laterally until it as assumed the form of a tube of about half the original diameter with two flat flan or ribs projectin radially therefrom 180 degrees apart. T ese flan s are shown at 3, 3 and are of a double t ickness of sheet metal and are formed by the surplus metal of the original tube over what is required for the smaller tube. The two ends of the tube are left of the ori inal size and form, but have a screw threa 2 rolled or pressed in them.

Inside the central tube of the shell and in heat conducting proximit thereto there is extended a lining 4 of re actory insulation formed in a series of short sections abutting-not telescoping into-one another. Inside of the lining is the heating coil 5. This heating coil as a distinct artlcle of manufacture is shown in Fig. 5. To each end of the coil is attached a rod or stem 6 of metal by the following means On the end of rod 6 is screwed a ferrule, or enlargement, 16, shown on a greater scale in Figs. 2 and 3. In the outer surface of ferrule 16 a helical groove 19 is scored and several of the end turns of coil 5 are laid in this groove. Then the ferrule is swaged down compressing the edges of groove 19 on the wire therein, leaving the outsideappearance of the ferrule as shown in Fig. 3. This expedient has manifold merits. The swaging produces Y a perfect electrical contact between the ferrule and the wire of the coil. It does not cause undue stress on the wire as does a twisted joint. It is mechanically stron and permanent and cannot work loose. t is not afected by heat as a soldered joint is, while some resistant heater-wire does not solder well, even if the heat were not too great; but in most cases the operation of the Yheater gives a temperature too high for a soldered joint. It is also neat and substantial in appearance which is important, since the coils are sold separately for replacements, and it is also inexpensive.

Furthermore by including between the permanent terminals a predetermined length of wire I insure the use at all times of a correct length of coil, there being otherwise dan r of a too short wire being used, the coil eing easily extended by drawin it out, with the result of overheating and estruction of the coil, since the correct length can only be ascertained by accurate resistance measurements and computations which it is not practicable for the ordinary user of the coil to make. Since the coil is so elastic longitudinally, its length at any moment ives no accurate idea of the length of wire it contains. With a detachable terminal a considerable amount of wire might be cut or broken off and the terminal reconnected without causing any perception of the loss by the appearance of the coil. If then put in service the coil would overheat by reason of its loss of length and consequent loss of resistance. This is prevented by making the coil a complete unit in itself with ermanent terminals between which a pre etermined length of wire is included. In addition I provide a flattened enlargement 13 on one or both of the Shanks of the stems 6 whereon are stam ed appropriate data to identify the coil an prevent its being used in an improper situation. The flattened s ace on the shank is also of value in assemb ing the heater, as will be hereinafter explained, while the shank is made long in order to kee the heat away from the insulating seal an the metal parts carried thereby-in particular from the insulation of the outside lead-wire 21 which is not likely to be of heat-proof quality. The length of the stein 6 (which is also of low heatconducting metal) should be such that such heat as there ma be at the end ofthe coil will be conducte out laterally through the lining 4 to the shell 1 rather than along stem 6.

Moreover, I prefer to secure the stem `6 in the ferrule 16 with a fusible solder that will melt at a determined degree of heat. Since the coil is under tension the melting of the solder will release the coil and suddenly break the circuit by the se aration of the ferrule and the stem 6. T is fusible solder is shown at W in Fig. 9. Each stem 6 is screwed into a metal block or insert 8 that is tightly set into an insulating bushing 9 which, in turn, is screwed into or locked in the end of the metallic shell 1. The outer end of insert 8 is countersunk at 20 and in the bottom of the countersink is the screw hole for binding-screw 10 b which the outside lead-wire is connecte to trie insert. The countersink 20 allows the screw to be centered and engaged with the insert independently of the screw thread which it subse uently enga es. The bushing 9 is preferably of molde refractory material and is provided with a shoulder 11 which abuts against the end of th( shell 1 and seals the screw joint. In its outer end is a screw threaded circular recess or opening '22 in which a (perforated plug 15 may be screwed if desire In the bottom of said recess 22 is a square or polygonal depression 12 for receiving a socket wrench to screw the bushing in the shell 1. Since this square hole or deplression is at the bottom of the recess 22, lia ility of splitting the bushing when screwing it into the shell is materially limited. Since replacement of coils is a necessary practice in the manufacture and use of heaters of this kind, the features I have described become of large im ortance in rendering the heater available or practical service, especial] to persons more or less inexpert in electrical matters.

Fig. 4 illustrates the aforesaid supplementary treatment of the shell after it has been first rolled or pressed into shape and the lining 4 inserted. In this Figure 17 and 18 indicate rolls with deep grooves between which the tube is passed. In this operation the edges of the roller grooves draw in the metal tightly around theY lining 4, the walls of the iianges 3, 3, being left slightly separated to ermit said drawing-in action. This avoi s crushing of the lining and secures the lining in the shell sufficiently to maintain it in the shell while the coil is thrust, or threaded, through it.

The mode of assembling4v the aforesaid parts is as follows: Assuming the lining 4 is in place in the shell 1, the coil 5, having both of its permanently connected terminals 6 secured thereto, one of said terminals is first screwed into the insert 8 of one bushing 9.

Then the opposite end of the coil with its attached terminal is inserted in the lining with a cord or wire secured to it temporarily and the bushing 9, now attached to the rear end of the coil, is screwed into the shell by a socket wrench in the polygonal depression 12. At the other end of the shell the stem 6 of the inserted coil may be pulled out by said cord or wire and gripped by pliers so that its insert 8 can be screwed on it before its bushing 9 is screwed into the shell. The flat place 13 allows the stem to be held without rotating in the pliers. Prior to screwing said second bushing into the shell it may be turned reversely a few times putting a slight reverse twist in the coil which is Asubsequently uiitwisted vwhen the bushing is screwed home on the shell. The coil is thus left in its normal condition. Moreover, this normal condition of the coil is a condition of tension produced by drawing its looseend out to secure it to the con responding insert. The result is that, in the event of a breakage of the coil, due for instance to a suddenly applied high voltage. the severed ends snap back and 'instantly rupture the arc formed by the break. That action is similar to the circuit-breaking action above described which occurs when the fuse between ferrule 16 and stem 6 is melted by heat. By this means the accident aforesaid, which would otherwise cause e violent explosion and report, becomes hnrdlr perce tible y virtue of the easy placement and replacement of the coil, it becomes possible to provide one standard shell and lining for nearly all types and sizes of heater. These standard shells ma)T be kept in stock together with a variety of coils for dii-ferent voltages and current values, as stumped on the marker-plate 13. Then the user or retailer can insert any desired coil in a standard shell. Heretofore the electric heater trade has dealt only in completed heaters. That practice is changed by my invention and the electric heater business may nour be lar rely in shells and coils which I have ma e separate articles of manufacture.

In Figxli I have shown in place of the external ivire 21 an adapter-plate 23, having its lower end bent over and connected to the insert 8 aforesaid by the binding screw 1,0. The end recess in bushing 9 may, if desired, be filled with a plastic material 25, or may be left o en. The plate 23 is shown as bolted to a 11s-bar 21. This involves no structural change in the heater itself and illustrates its capacity for service under different circumstances. In this ease a number of heatersimy'be similarly connected to the bus-bar 24, a vain in output of heat being secured by mu tiplying the standardV heater units rather than by increasing the size of the heater itself,

In Fig. 7 I have shown the heater shell as provided with local insulation which may be in the form of rings 28 of molded material surrounding the tubular ends of the shell. For this purpose the threads on the shell are replaced near the outer end with a cylindrical seat for the ring having unges on either edge to retain the ring in position thereon. The rinor may be used as the means for supporting tthe heater as ap ears in the figure. The entire bracket may lane of insulation if desiredy und the rings 28 may be square or. of any other shape. Since the ring t28 is a. permanent part of the heater applied at the natural point of support, the heater will normally be mounted so as to in sulntc the shell :is well as the coil, whereby. in the event of an accidental connection between the coil and shell the current in the coil will not escape.

In Fig. 8 I have shown a heater shell in the form of n bcndahle metallic tube 2li. This tnli'c maiv he of soft copper or other flexible mhenclablc material but I prefer to construct it of overlapping helical plates a and b, Inside of the tube is the refractor?,- lining formed of short sections 4", 4*

Y which are of such shape that the)r mai7 asslnnc a slightly angular relation to one another as the t-ubc assumes a bent or curved position. To each end of the iexible tube is secured a short rigid pipe 27 wherein is contained the hushinfv 9 such as l have already described. Within the lining aforesaid is the heating Coil with its Connected stem 6 as heretofore explained.

In Fig. 9 the stem 6 is connected to ferrule 1li by 'a fuse W, as heretofore mentioned. In the crent of the fuse melting and the coil itself acting to separate 16 und 6 the arc will be formed between the terminal 16 and the stein G und will not ail'ect the wire of the coil, which, as aforesaid, is sivaged in the terininal 16. In this case I :idd a refractory annular tip to the ferrule 16 to help extinguish the are.

What I claim as new and desire to secure shell, a refractory lining therefor, a heating' coil in seid lining, and an insulating bushing for each end of the shell having n. screw thread t-ting e corresponding thread adn tliI recess in its en an shell with an externa a polygonal depressionin'the'bottom of the recess.

3. An insulatn bushing for closing the end of an electricieater shell provided with a screw thread and having on its outer end-'a recess in the bottom of which is a polygonal de ression.'

4. An insu ating bushi for closing the end of anelectric-heater s ell containing a metallic block for `commotion with the heater coil, a recess at its outer end', a polygonal depression at the bottom of the recess and a binding connector in said depression or connecting said' block to the external circuit.

5. An insulating bushin for closing the end of an electric-heater siell containing a metallic block which has at its outer en aV binding-screw hole Witha-conntersink enlargement,

6. Aninsnlating bushin for closing the end of an electric-heater ell having a recess at its outer cud and a. metallic block for the coil-connection having at the 'bottom of' scid recess a binding-screw hole' with a countersunk enlargement.

7. An electric heater comprising a metallic shell, a tubular refractory Iinin side the shell, a heating co1 extended through said lining, coil-terminals passin through insulation 1n the shell, and externa insilillation applied .to the outside of said she 8. An electric heater com rising a metallic shell, a tubular refractory ining fitting thel inside of said shell, a heating coil extendlitting in-I ing through said shell, coilter1ninals passing th rough insulation, and external, insulating supports secured to the shell.

SJ. An olectricheuter comprising a metallic shell, n refractory lining fitting the inside Y in Vthe form of a instal tube having ribs on its cent-ral portion and circular endsz, arefrnictory tubulailining extendnu through said shell undl fit-tin the interior thereof, u heating-'coil in sui .lining,icoilterniinu.ls passing through bushin 4 on each eindof-the shell, -and en ,externs insulating supporton' each of the circular ends of the shell. .I

12. .An electric heatercomprising ai metal shell .having ribs onits central portion and circular .screw-threaded ends, a refractory tubular linin fitting the inside of saidshell,-

s, heating co1 in said lining coil-terminals extending through screw-threaded .bushings in .each endof the shell, and external insulation embracin and secured outside of'each endoftheshel.

13. The method of forming an electric heater -which consists in securing a. metal shell onV s refractory tube contained therein, und threading a heating coilV throughsaid tubo after it place 1n the shell.

414. The method of forming an electric heaterwhich consists in securing a, metal shell-on a. refractory tube contained therein, threadingn heat-in coil with an attached terminal thereon t rough seid refractory tube .and securing the seid terminal in an isililseiliilating bushing in the farther end of said 15. The method of forming heater which consists in secunn tory tube within a. metallic shel passing one end ofaheatin coil provided with an attached rigid terminal through said tube, and securing each terminal. o said coil in an insulating bushing on the metallic shell.

1G. The Inode of forming an electric heuter which consists in securing a. refractory tube inside of n .metallic shell, assin through said tube one end of u heating coil having a. ri id terminal permanently secured to eaci of its ends, and securing the two rigid terminals successive] in bus iings at the respective ends of the s ell.

17. The method of forming an electric heaterwhich consists in securing a refractory tube inside of a metallic shell, paing through un electric s. refraccoil having aV rigid screw-threaded terminal secured to each end, and successively screwinw each of the seid terminals into un insu atinlg bushing at the end of the heater.

18. he mode of forming an electric heater which consists ,in pressing ,at metallic shell into its a proximate shape,-,inserting. therein a, tubucr lining of refractory material, comprcssinmthe metal shell around said'lining, and. then threading. a. heating coil through said lining and connecting its ends to lsuitable binding .connecto1s v19. The mode of formingsn electric hecter4 which4 consists in pressmv. a metal shell into the forrnbf-a tube witl inserting1 in, the tubular. partn, perforated lining of refractory lnuteriah passing the shell between ,grooved pressing agents to draw the metalfthereofsecurely around said liningA andthen passing the ,heating coil through the. perforation ofthe lining.

"20. vAs snarticle-of manufacture, a. metallic electric-heater shell of tubular form having,cl osely. fitting refractory, lining tl1erein.` l

2l. As an article of manufacture a metallic electric-heater shell oftub ler form havingn closelyhttinglining of refractory material. therein.; V

.22.. Yfrs-an crticleofn'mnufacture, a metallic electric-,lieen shellharin a refractory lining theremfcornposed of. tu ular sections.

. 23. .As an .article ofmanufccturc, a metallic. electric-heater shell of tubular form havin therein a refractory liningcomposed of tu ular. sections MQlmd- Awhich themetal of the shell is compressed.

24. As anlarticleof manufacture, a metallic electric-heater. shell of tubular form with ribs thereon andlhaving. a, refractory lining therein composed of a. series of tubular sections closely {it-ting4 the shell.

25.- As an article of manufacture, a metallicelectric-heaterrshell of tubular form with an inte ral rib thereon having a refractory lining t erein composed of a series of tubular sections closely fitting the shell.

26. As an article of manufacture, e metallic electric-heater shell compressed into tubular form withan integral rib thereon and having therein a iefractory lining closely ttin the shell and composed of n series of tu ular sections.

27. .As an article of manufacture, a metallic electric-heater shell formed by pressing a tube into u tube of smaller diameter with doubled integral Hongos on both sides and having a closely tting lining of refractory material.

2S. As an article of manufacture, an electric-heater coil having rigid terminals permanently secured thereto and a. predetermined length of wire between said terminals.

29. As nn article of manufacture, an elecsaid refractory tube one end of aheating tric-heater coillhaving rigid screw-threaded i parallel ribs,l

terminals permanently secured thereto and a predetermined length of wire between the said terminals.

30. As an article of manufacture. an electric-heater coil having rigid terminals permanently secured thereto having a maximum diameter not exceeding substantially the diameter of the coil with a predetermined length of wire between said telminals.l

31. As an article of manufacture, an electric-heater coil having its ends swaged into rigid terminals between which is a predetermined length of wire.

32. As an article of manufacture, an electric-heater coil having at each end and permanently secured thereto a combined connection-terminal and marker with a predetermined len h of wire between the two.

33. An electrlc-heater coil rovided with a terminal having a helica groove into which the end of the coil is swaged.

34. The combination with a wire coil of a terminal therefor of substantially the diameter of the coil and having a helical groove therein into which the wire of the coil is threaded and swa ed.

35. The combination with a wire coil of a terminal therefor of substantially the diameter of the coil and having an external groove forming acontinuation of the coil helices into which the wire of the coil is threaded and swaged.

36. The combination with an electricheater coil of a terminal therefor having an enlarged end to which the wire of the coil is secured and a reduced shank of limited heat-conducting capacity.

37. The combination with an electricheater coil of a terminal therefor having an enlarged end t which the wire of the coil is secured and a reduced shank of limited heat conducting capacity on which are characters identifying the coil.

38. The combination with an electricheater coil of a terminal permanently connected thereto on which are characters identifying the coil.

39. The combination with an electricheater coil of terminals permanently Secured thereto having a screw-threaded portion of reduced heat-conducting capacity.

40. An electric heater comprising a meta lic shell, a refractory tubular linm therefor in close contact therewith, a eating coil in said lining, an insulated metallic block for connection to the external circuit, and a connector of reduced heat-conducting capacit between said block and the end of the co' 41. An electric heater comprising a metallic shell, a tubular refractory lining closely fitting the shell. a heating coil in said lining, a metallic block insulated from the shell for receiving the external circuit 00nnection. and an elongated coil-terminal between the block and coil for restricting the transmission of heat from the coil to said block. y

42. A11 electric heater comprising a pressed metal shell of tubular ribbed form with circular ends. a cosely fitting lining in said shell formed of tubular sections, an

insulating bushing in each of said ends with an outer recess. a metallic block extending through said bushing from the bottom of said recess, a heating coil extending through the liningr with an elongated terminal between the end of the coil and the said metallic block.

43. An electric heater comprising a metal- Yic shell, a refractory tubular lining closely fitting the interior of said shell, an insulatiug bushing sealing the end of the shell, a

separable heating coil extending through 45. An electric heater comprising a. metal tube. a refractory lining fitting the tube, a coil in said lining separable therefrom, coilterminals of larger diameter than the wire of the coil. and an insulatino` bushing thru h which the said terminals are exten 46. An electric heater comprising a metal tube` a refractory lining therefor. a heating coil in said lining separable therefrom, coil-terminals secured to the ends of the coil, and insulated metal blocks with which said terminals are separably connected for receiving the external-circuit wire.

47. An electric heater comprising a. metal tube, a refracto lining therefor, a heating coil in said lining separable therefrom, an insulating bushing recessed externally, a coil-terminal connected to a metal block located in said bushing below the recess and a rigid connector extending outwardly from said block.

48. An electric heater comprising a tube or duct of refractory insulating material and a heating element therein consisting of a coil of resisting wire of such diameter with respect to the tube or duct as to slide freely therethrough.

49. An electric heater comprising a tube or duct of refractory insulation and a. heater element consisting of a coil of resisting wire havingatermmalattachod thereto,bothw coil and terminal being of such diameter with respect to the tube or duct as to slide freely therethrough.

50. An electric heater containing a heating coil under tension land a fusible retainer therefor.

51. An electric heater comprising two or more component coils in the same heatin circuit each provided with an individuav fuse.

52. An electric heater comprisin an insulating duct of refractory materia a heating coil therein, and a fuse for the coil contained in the said duct.

53. An electric heater comprising a metal casing, a refractory lining therein, and a removable heating coil and fuse therefor within said lining.

54. An electric heater comprising an elastic heating coil under tension, a terminal for the coil and a retaining fuse between said terminal and a fixed part of the heater.

55. An electric heater comprising an elastic heating coil under tension, two members capable of sliding on each other one connected to the said coil, the other to a fixed part of the heater and a fusible retainer between said members.

56. An electric heater comprisin a refractory insulating tube, an elastic eating coil therein under tension, a terminal attached to said coil and capable of longitudinal movement in said tube, and fusi le retaining means for said terminal.

57. An electric heater comprising a refractory insulating container, an elastic heating coil in sald container under tension and having free lay therein, and fusible retaining means or said coil.

58. An electric heater comprising a refractory insulating container, an elastic heating coil in said container under tension, a two-part terminal for said coil, and a usible retainer between the two parts.

59.' An electric heater compris' a refractory insulating tube, an elastic eating coil thereon fitting the tube but havin free pla therein, means for holding said coil un er tension and a fusible retainer for said means.

60. An electric heater comprising a refractory insulatin container, an elastic heating coil therein eld under tension, a terminal for said coil, a terminal extension of reduced heat-conducting capacity, and fusible retaining means between said terminal and its extension..

61. An electric heater comprising a duct of refracto insulating material, an extension of sald duct containing an insulated block for the external circuit connection, an elastic heating coil in said duct free to pass longitudinally therein, and a terminal memberbetween said coil and the said insulated block.

62. The method of formin an electric heater which consists in first p acing in permanent position a refractory insulating tube, passing through said tube a heating coil of less diameter and securing the respec" tive ends of the coil to insulated connection blocks.

63. The method offorming an electric heaterwhich consists in placing a rerac-f tory insulating tube in its permanent position, threading through said tube an elastic, extensible heating coil, normally shorter than the tube, securing one end of said coil, drawing theopposite end out beyond .the end of the tube, securing thereto a terminal block for connection with the external circuit and allowing the coil to rest in the tube in a condition of tension.

Signed at Albany, county of Albany, State of New York, this 20t day of January, 1922.

LEE P. HYNES. 

